Olefin-based polymer

ABSTRACT

The present invention relates to an olefin-based polymer, which has (1) a density (d) ranging from 0.850 g/cc to 0.865 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min, (3) a melt temperature (Tm) of 10° C. to 100° C., and (4) a hardness (H, Shore A), the density (d) and the melt temperature (Tm) satisfying Equation 1, and Equation 2 or 3. The olefin-based polymer according to the present invention has low hardness and improved foaming properties, and exhibits improved impact strength at compounding.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2018/016468 filed Dec. 21, 2018, which claims priority from Korean Patent Application No. 10-2017-0178329 filed Dec. 22, 2017, all of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an olefin-based polymer, and specifically, to a low-density olefin-based polymer prepared using two types of transition metal compound catalysts, which has a low hardness and improved foaming properties and exhibits improved impact strength at compounding.

BACKGROUND ART

Polyolefins are widely used for extrusion-molded articles, blow-molded articles and injection-molded articles due to excellent moldability, heat resistance, mechanical properties, hygienic quality, water vapor permeability and appearance characteristics of molded articles thereof. However, polyolefins, particularly polyethylene, have a problem of low compatibility with polar resins such as nylon because of the absence of polar groups in the molecule, and low adhesiveness to polar resins and metals. As a result, it is difficult to blend the polyolefin with polar resins or metals, or to laminate the polyolefin with these materials.

Further, a molded article of a polyolefin has a problem of low surface hydrophilicity and a low antistatic property.

In order to solve such a problem and to increase the affinity for a polar material, a method of grafting a polar group-containing monomer onto a polyolefin through radical polymerization has been widely used. However, this method has a problem in that cross-linking in the molecules of the polyolefin and cleavage of molecular chains occur during the grafting reaction, and the viscosity balance of a graft polymer and a polar resin is poor, and thus miscibility is low. There is also a problem in that the appearance characteristics of a molded article are low due to a gel component generated by intramolecular crosslinking or a foreign substance generated by cleavage of molecular chains.

Further, as a method of preparing an olefin polymer such as an ethylene homopolymer, an ethylene/α-olefin copolymer, a propylene homopolymer or a propylene/α-olefin copolymer, a method of copolymerizing a polar monomer in the presence of a metal catalyst such as a titanium catalyst or a vanadium catalyst was used. However, when the above-described metal catalyst is used to copolymerize a polar monomer, there is a problem that the molecular weight distribution or composition distribution is wide, and polymerization activity is low.

As another method, a method of polymerizing in the presence of a metallocene catalyst including a transition metal compound such as zircononocene dichloride and an organoaluminum oxy compound (aluminoxane) is known. When a metallocene catalyst is used, a high-molecular weight olefin polymer is obtained with high activity, and the resulting olefin polymer has a narrow molecular weight distribution and a narrow composition distribution.

Further, as a method of preparing a polyolefin containing a polar group using a metallocene compound having a ligand of a non-crosslinked cyclopentadienyl group, a crosslinked or non-crosslinked bisindenyl group, or an ethylene crosslinked unsubstituted indenyl/fluorenyl group as a catalyst, a method using a metallocene catalyst is also known. However, these methods have a disadvantage in that polymerization activity is very low. For this reason, a method of protecting a polar group by a protecting group is carried out, but there is a problem that the process becomes complicated since a protecting group should be removed again after the reaction when the protecting group is introduced.

An ansa-metallocene compound is an organometallic compound containing two ligands connected to each other by a bridge group, in which the rotation of the ligand is prevented and the activity and structure of the metal center are determined by the bridge group.

The ansa-metallocene compound is used as a catalyst in the preparation of olefin-based homopolymers or copolymers. In particular, it is known that an ansa-metallocene compound containing a cyclopentadienyl-fluorenyl ligand can prepare a high-molecular weight polyethylene, thereby controlling the microstructure of the polypropylene.

Further, it is also known that an ansa-metallocene compound containing an indenyl ligand can produce a polyolefin having excellent activity and improved stereoregularity.

As described above, various studies have been made on ansa-metallocene compounds capable of controlling the microstructure of olefin-based polymers and having higher activity, but the research is still insufficient.

DISCLOSURE Technical Problem

An object of the present invention is to provide a low-density olefin-based polymer prepared using two types of transition metal compound catalysts, which has low hardness and improved foaming properties, and exhibits improved impact strength at compounding.

Technical Solution

In order to accomplish the object, the present invention provides an olefin-based polymer, which has (1) a density (d) ranging from 0.850 g/cc to 0.865 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min, (3) a melt temperature (Tm) of 10° C. to 100° C., and (4) a hardness (H, Shore A), a density (d) and a melt temperature (Tm) satisfying the following Equation 1: H=1293×d+A  [Equation 1]

In Equation 1, A satisfies Equation 2 or Equation 3 below. Tm×(0.855×Tm−62)<A<d×−1238  [Equation 2] d×−1238<A<Tm×(0.855×Tm−62)  [Equation 3]

Advantageous Effects

The olefin-based polymer according to the present invention is a low-density olefin-based polymer having low hardness and improved foaming properties, and exhibits improved impact strength at compounding.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail to assist in the understanding of the present invention.

Terminology used in the specification and claims should not be construed as limited to conventional or literal meanings, and should be construed as having meanings and concepts corresponding to the technical idea of the present invention based on the principle that the inventor can suitably define the concept of a term to explain his own invention in the most preferable way.

In the specification, the term “a polymer” denotes a polymer compound prepared by the polymerization of monomers having the same or different types. The general term “the polymer” includes “a hybrid polymer” as well as “a homopolymer,” “a copolymer” and “a terpolymer.” Further, “the hybrid polymer” denotes a polymer prepared by the polymerization of at least two different types of monomers. The general term “the hybrid polymer” denotes “the copolymer” (commonly used for denoting a polymer prepared using two different types of monomers) and “the terpolymer” (commonly used for denoting a polymer prepared using three different types of monomers). “The hybrid polymer” includes a polymer prepared by the polymerization of at least four different types of monomers.

An olefin-based polymer according to the present invention satisfies the following conditions of (1) to (4):

(1) a density (d) ranging from 0.850 g/cc to 0.865 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min, (3) a melt temperature (Tm) of 10° C. to 100° C., and (4) a hardness (H, Shore A), a density (d) and a melt temperature (Tm) satisfying the following Equation 1. H=1293×d+A  [Equation 1]

In Equation 1, A satisfies Equation 2 or Equation 3 below. Tm×(0.855×Tm−62)<A<d×−1238  [Equation 2] d×−1238<A<Tm×(0.855×Tm−62)  [Equation 3]

Generally, the lower the density and the lower the hardness of the polymer, the better the foaming. The olefin-based polymer according to the present invention exhibits low hardness when it has a density of the same level as that of conventional olefin-based polymers while having a very low density, and thus can exhibit more excellent foamability.

The olefin-based polymer according to the present invention exhibits a density in the range of 0.850 g/cc to 0.865 g/cc, and more specifically, in the range of 0.853 g/cc to 0.863 g/cc when measured in accordance with ASTM D-792. The olefin-based polymer according to an embodiment of the present invention exhibits the low density as described above, and thus excellent foam processability and impact strength can be exhibited at compounding.

The melt index (MI) may be controlled by adjusting the amount of the catalyst used in the polymerization of the olefin-based polymer with respect to the comonomer, and affects the mechanical properties, impact strength and moldability of the olefin-based polymer. In the present specification, the melt index is measured at 190° C. under a load of 2.16 kg in accordance with ASTM D1238 at a low density of 0.850 g/cc to 0.865 g/cc, and may be in the range of 0.1 g/10 min to 3 g/10 min, specifically, in the range of 0.2 g/10 min to 2 g/10 min, and more specifically, in the range of 0.25 g/10 min to 1.8 g/10 min.

The olefin-based polymer may have a melt temperature (Tm) in the range of 10° C. to 100° C., specifically in the range of 10° C. to 80° C., and more specifically in the range of 10° C. to 60° C. obtained in a differential scanning calorimetry (DSC) curve obtained by DSC measurement.

The olefin-based polymer according to the present invention, a hardness (H, Shore A), a density (d) and a melt temperature (Tm) satisfies the following Equation 1. H=1293×d+A  [Equation 1]

In Equation 1,

H is a hardness; d is a density; and A satisfies Equation 2 or Equation 3 below. Tm×(0.855×Tm−62)<A<d×−1238  [Equation 2] d×−1238<A<Tm×(0.855×Tm−62)  [Equation 3]

In Equation 2 and 3, Tm is a melting point, and d is a density.

Further, the olefin-based polymer according to the present invention may have (5) a soluble fraction (SF) of 8 wt % or more, and specifically, in the range of 10 wt % to 50 wt % at −20° C. in cross-fractionation chromatography (CFC), and a weight average molecular weight (Mw) of the fraction may be maintained at 50,000 or more.

The fractions eluted at a low temperature in the cross-fractionation chromatography (CFC) measurement have low crystallinity. In the present specification, the soluble fraction eluted at a temperature of −20° C. or less in the cross-fractionation chromatography (CFC) is defined as an ultra-low crystalline region.

The olefin-based polymer according to an embodiment of the present invention has a high ultra-low crystalline content because the soluble fraction at −20° C. in the cross-fractionation chromatography satisfies the above-described range, and thus it is possible to exhibit excellent impact strength.

Further, a weight average molecular weight (Mw) of the soluble fraction of the olefin-based polymer according to an embodiment of the present invention may have 50,000 g/mol to 500,000 g/mol, more specifically, 50,000 g/mol to 300,000 g/mol, and more specifically, 60,000 g/mol to 200,000 g/mol. A weight average molecular weight (Mw) of the soluble fraction at −20° C. in cross-fractionation chromatography of the olefin-based polymer according to an embodiment of the present invention satisfies the above-described range, and thus the olefin-based polymer exhibits a high-molecular weight and an ultra-low crystalline content. In particular, the olefin-based polymer according to an embodiment of the present invention satisfies the density (1) and melt index (2), and the content of the soluble fraction and the weight average molecular weight (Mw) of the soluble fraction, and exhibits high soluble fraction content and high weight-average molecular weight of the soluble fraction.

Further, the olefin-based polymer according to an embodiment of the present invention may have (6) a molecular weight distribution (MWD), which is a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn), in the range of 1.0 to 3.0, specifically in the range of 1.5 to 2.8, and more specifically in the range of 1.8 to 2.6. The olefin-based polymer according to an embodiment of the present invention may be polymerized using a catalyst composition including two types of transition metal compounds having a characteristic structure, thereby exhibiting a narrow molecular weight distribution.

Generally, the density of the olefin-based polymer is affected by the type and content of the monomers used in the polymerization, the degree of polymerization and the like, and the copolymer is affected by the content of the comonomer. The olefin-based polymer of the present invention is polymerized using a catalyst composition containing two types of transition metal compounds having a characteristic structure, and a large amount of comonomers may be introduced, and the olefin-based polymer of the present invention has a low density in the range as described above, and as a result, excellent foam processability can be exhibited.

The olefin-based polymer may have (7) a weight average molecular weight (Mw) in the range of 10,000 g/mol to 500,000 g/mol, specifically in the range of 30,000 g/mol to 300,000 g/mol, and more specifically in the range of 50,000 g/mol to 200,000 g/mol in the above-described molecular weight distribution range. In the present invention, the weight average molecular weight (Mw) is a polystyrene-converted molecular weight which is analyzed by gel permeation chromatography (GPC).

Further, the olefin-based polymer according to an embodiment of the present invention may have a hardness (Shore A) of 50 or less, specifically 30 or more and less than 50, more specifically in the range of 35 to 48. The olefin-based polymer satisfies the above-described hardness value, and thus can exhibit excellent foamability and impact strength at compounding.

The olefin-based polymer according to an embodiment of the present invention can have the high soluble fraction eluted at a temperature of −20° C. in cross-fractionation chromatography (CFC), maintain the molecular weight of the soluble fraction at a high value and exhibit low hardness at the same level of density and melt index value as compared to conventional olefin-based polymers.

Specifically, when the olefin-based polymer according to an embodiment of the present invention satisfies the density in the range of 0.855 g/cc to 0.865 g/cc and the melt index (MI) in the range of 0.5 g/10 min to 2 g/10 min, a soluble fraction (SF) at −20° C. in cross-fractionation chromatography (CFC) may be 8 wt % or more, and a weight average molecular weight (Mw) of the fraction may be maintained at 60,000 or more. The olefin-based polymer according to an embodiment of the present invention can have the high soluble fraction eluted at a temperature of −20° C. in cross-fractionation chromatography (CFC), maintain the molecular weight of the soluble fraction at a high value and exhibit low hardness at the same level of density and melt index value as compared to conventional olefin-based polymers.

Further, when the olefin-based polymer according to an embodiment of the present invention satisfies the density in the range of 0.855 g/cc to 0.865 g/cc and the melt index (MI) in the range of 0.95 g/10 min to 1.2 g/10 min, a hardness (Shore A) may be 50 or less, specifically 30 or more and less than 50, more specifically in the range of 35 to 48. The olefin-based polymer according to an embodiment of the present invention exhibits relatively low hardness at the same level of density and melt index as compared with conventional olefin-based polymers, and thus can exhibit excellent foamability.

Further, the olefin-based polymer according to an embodiment of the present invention may have a density (d) ranging from 0.850 g/cc to 0.865 g/cc; a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min; a hardness (H, Shore A), a density (d) and a melt temperature (Tm) satisfying the following Equation 1; a soluble fraction (SF) of 10 wt % or more at −20° C. in cross-fractionation chromatography (CFC), in which a weight average molecular weight (Mw) of the fraction is in a range of 50,000 g/mol to 120,000 g/mol; a vinyl group content per 1,000 carbon atoms of 0.06 to 1, which determined by infrared absorption measurement; and a MFR10/MFR2.16 of 8.5 or less, which is a ratio of the melt flow rate measured according to ASTM D1238 at 190° C. 10 kg load and according to ASTM D1238 at 190° C. 2.16 kg load: H=1293×d+A  [Equation 1]

In Equation 1, A satisfies Equation 2 or Equation 3 below. Tm×(0.855×Tm−62)<A<d×−1238  [Equation 2] d×−1238<A<Tm×(0.855×Tm−62)  [Equation 3]

The olefin-based polymer is a homopolymer or two or more copolymers selected from an olefin-based monomer, specifically, an alpha-olefin-based monomer, a cyclic olefin-based monomer, a diene olefin-based monomer, a triene olefin-based monomer, and a styrene-based monomer. More specifically, the olefin-based polymer may be a copolymer of ethylene and an alpha-olefin having 3 to 12 carbon atoms or 3 to 10 carbon atoms.

The alpha-olefin comonomer may include any one or a mixture of two or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, norbornene, norbornadiene, ethylidene norbornene, phenyl norbornene, vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene and 3-chloromethyl styrene.

More specifically, the olefin copolymer according to an embodiment of the present invention may be a copolymer of ethylene and propylene, ethylene and 1-butene, ethylene and 1-hexene, ethylene and 4-methyl-1-pentene or ethylene and 1-octene, and more specifically, the olefin copolymer according to an embodiment of the present invention may be a copolymer of ethylene and 1-octene.

When the olefin-based polymer is a copolymer of ethylene and an alpha-olefin, the amount of the alpha-olefin may be 90 wt % or less, more specifically 70 wt % or less, still more specifically in the range of 5 wt % to 60 wt % and even more specifically in the range of 20 wt % to 50 wt % with respect to the total weight of the copolymer. When the alpha-olefin is included in the above-described range, it is easy to realize the above-mentioned physical properties.

The olefin-based polymer according to an embodiment of the present invention, which has the above-described physical properties and constitutional characteristics may be prepared by a continuous solution polymerization reaction in the presence of a metallocene catalyst composition including at least one type of a transition metal compound in a single reactor. Accordingly, in the olefin-based polymer according to an embodiment of the present invention, a block formed by linearly connecting two or more repeating units derived from one monomer among monomers constituting a polymer in the polymer is not formed. That is, the olefin-based polymer according to the present invention does not include a block copolymer, but may be selected from the group consisting of a random copolymer, an alternating copolymer and a graft copolymer, more particularly, may be a random copolymer.

Specifically, the olefin-based copolymer of the present invention may be obtained by a preparation method including a step of polymerizing olefin-based monomers in the presence of a catalyst composition for olefin polymerization including a transition metal compound represented by the following Formula 1 and a transition metal compound represented by the following Formula 2 in an equivalent ratio of 1:1 to 1:5, specifically, of 1:1 to 1:4.

However, in the preparation of an olefin-based polymer according to an embodiment of the present invention, the structure ranges of the first transition metal compound and the second transition metal compound are not limited to specifically disclosed types, and all modifications, equivalents, or replacements included in the scope and technical range of the present invention should be understood to be included in the present invention.

In Formula 1,

R₁ may be the same or different, and each independently represent hydrogen, an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, an aryl, a silyl, an alkylaryl, an arylalkyl or a metalloid radical of a Group 4 metal substituted with a hydrocarbyl, and the two R₁ may be connected together by alkylidene radicals including an alkyl having 1 to 20 carbon atoms or an aryl radical having 6 to 20 carbon atoms to form a ring;

R₂ may be the same or different, and each independently represent hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; an aryl; an alkoxy; an aryloxy; or an amido radical, and two or more of the R₂ may be connected to each other to form an aliphatic ring or an aromatic ring;

R₃ may be the same or different, and each independently represent hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; or an aliphatic or aromatic ring which contains nitrogen and is substituted with an aryl radical or unsubstituted, and when the number of substituents is plural, two or more substituents among the substituents may be connected to each other to form an aliphatic or aromatic ring;

M₁ is a Group 4 transition metal;

Q₁ and Q₂ each independently represent a halogen; an alkyl having 1 to 20 carbon atoms; an alkenyl; an aryl; an alkylaryl; an arylalkyl; an alkylamido having 1 to 20 carbon atoms; an arylamido; or an alkylidene radical having 1 to 20 carbon atoms;

In Formula 2,

R₄ may be the same or different, and each independently represent hydrogen, an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, an aryl, a silyl, an alkylaryl, an arylalkyl or a metalloid radical of a Group 4 metal substituted with a hydrocarbyl, and the two R₄ may be connected together by alkylidene radicals including an alkyl having 1 to 20 carbon atoms or an aryl radical having 6 to 20 carbon atoms to form a ring;

R₅ may be the same or different, and each independently represent hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; an aryl; an alkoxy; or an aryloxy; an amido radical, and R₅ may be connected to each other to form an aliphatic ring or an aromatic ring;

R₆ may be the same or different, and each independently represent hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; or an aliphatic or aromatic ring which contains nitrogen and is substituted with an aryl radical or unsubstituted, and when the number of substituents is plural, two or more substituents among the substituents may be connected to each other to form an aliphatic or aromatic ring;

M₂ is a Group 4 transition metal;

Q₃ and Q₄ each independently represent a halogen; an alkyl having 1 to 20 carbon atoms; an alkenyl; an aryl; an alkylaryl; an arylalkyl; an alkylamido having 1 to 20 carbon atoms; an arylamido; or an alkylidene radical having 1 to 20 carbon atoms.

Further, in another embodiment of the present invention, in Formula 1, R₁ and R₂ may be the same or different, and each independently may represent hydrogen; an alkyl having 1 to 20 carbon atoms; an aryl; or a silyl,

R₃ may be the same or different, and may be an alkyl having 1 to 20 carbon atoms; an alkenyl having 2 to 20 carbon atoms; an aryl; an alkylaryl; an arylalkyl; an alkoxy having 1 to 20 carbon atoms; an aryloxy; or an amido; and two or more adjacent R₃ among the R₃ may be connected to each other to form an aliphatic or aromatic ring;

Q₁ and Q₂ may be the same or different, and each may independently represent a halogen; an alkyl having 1 to 20 carbon atoms; an alkylamido having 1 to 20 carbon atoms; or an arylamido,

M₁ may be a Group 4 transition metal.

Further, in Formula 2, R₄ and R₅ may be the same or different, and each may independently represent hydrogen; an alkyl having 1 to 20 carbon atoms; an aryl; or a silyl,

R₆ may be the same or different, and may be an alkyl having 1 to 20 carbon atoms; an alkenyl having 2 to 20 carbon atoms; an aryl; an alkylaryl; an arylalkyl; an alkoxy having 1 to 20 carbon atoms; an aryloxy; or an amido; and two or more R₆ among the R₆ may be connected to each other to form an aliphatic or aromatic ring;

Q₃ and Q₄ may be the same or different, and each may independently represent a halogen; an alkyl having 1 to 20 carbon atoms; an alkylamido having 1 to 20 carbon atoms; or an arylamido,

M₂ may be a Group 4 transition metal.

Further, in the transition metal compound represented by Formula 1 or Formula 2, a metal site is connected by a cyclopentadienyl ligand to which tetrahydroquinoline is introduced, and the structure thereof has a narrow Cp-M-N angle and a wide Q₁-M-Q₂ (Q₃-M-Q₄) angle to which a monomer approaches. In addition, Cp, tetrahydroquinoline, nitrogen and the metal site are connected in order via the bonding of a ring shape to form a more stable and rigid pentagonal ring structure. Therefore, when these compounds are activated by reacting with a cocatalyst such as methylaluminoxane or B(C₆F₅)₃ and then applied to olefin polymerization, an olefin-based polymer having characteristics such as high activity, high molecular weight, high copolymerization properties and the like may be polymerized even at a high polymerization temperature.

Each of the substituents defined in the present specification will be described in detail as follows.

In the present specification, unless particularly defined otherwise, a hydrocarbyl group means a monovalent hydrocarbon group having 1 to 20 carbon atoms formed only with carbon and hydrogen regardless of its structure such as an alkyl group, an aryl group, an alkenyl group, an alkinyl group, a cycloalkyl group, an alkylaryl group and an arylalkyl group.

The term “halogen” used in the present specification, unless otherwise specified, refers to fluorine, chlorine, bromine and iodine.

The term “alkyl” used in the present specification, unless otherwise specified, refers to a linear or branched hydrocarbon residue.

The term “alkenyl” used in the present specification, unless otherwise specified, refers to a linear or branched alkenyl group.

The branched chain may be an alkyl having 1 to 20 carbon atoms; an alkenyl having 2 to 20 carbon atoms; an aryl having 6 to 20 carbon atoms; an alkylaryl having 7 to 20 carbon atoms; or an arylalkyl having 7 to 20 carbon atoms.

According to an embodiment of the present invention, the aryl group preferably has 6 to 20 carbon atoms, and specifically includes phenyl, naphthyl, anthracenyl, pyridyl, dimethylanilinyl, anisolyl and the like, but is not limited thereto.

The alkylaryl group refers to an aryl group substituted with the alkyl group.

The arylalkyl group refers to an alkyl group substituted with the aryl group.

The ring (or a heterocyclic group) refers to a monovalent aliphatic or aromatic hydrocarbon group which has a ring atom with 5 to 20 carbon atoms and contains one or more heteroatoms, and may be a single ring or a condensed ring of two or more rings. Further, the heterocyclic group may be unsubstituted or substituted with an alkyl group. Examples thereof include indoline, tetrahydroquinoline and the like, but the present invention is not limited thereto.

The alkylamino group refers to an amino group substituted with the alkyl group, and includes a dimethylamino group, a diethylamino group and the like, but is not limited thereto.

According to an embodiment of the present invention, the aryl group preferably has 6 to 20 carbon atoms, and specifically includes phenyl, naphthyl, anthracenyl, pyridyl, dimethylanilinyl, anisolyl and the like, but is not limited thereto.

The compound of Formula 1 may be one or more selected from the group consisting of the following Formulae 1-1 and 1-2, and the compound of Formula 2 may be the following Formula 2-1, but the present invention is not limited thereto.

In addition, it may be a compound having various structures within the ranges defined in Formulae 1 and 2.

The transition metal compound of Formula 1 and the transition metal compound of Formula 2 allow introduction of a large amount of an alpha-olefin as well as low-density polyethylene due to the structural characteristics of the catalyst, and thus it is possible to prepare a low-density polyolefin copolymer having a density in the range of 0.850 g/cc to 0.865 g/cc. Further, when the transition metal compound of Formula 1 and the transition metal compound of Formula 2 are used together in an equivalent ratio of 1:1 to 1:5, and specifically of 1:1 to 1:4, an olefin-based polymer having a high molecular weight, a narrow molecular weight distribution, a low density and a low hardness may be prepared.

For example, the transition metal compounds of Formulae 1 and 2 may be prepared by the following method.

In Reaction Scheme 1, R₁ to R₃, M₁, Q₁ and Q₂ each are as defined in Formula 1.

Further, the transition metal compound of Formula 2 may be prepared by the following method as an example.

In Reaction Scheme 2, R₄ to R₆, M₂, Q₃ and Q₄ each are as defined in Formula 2.

Formulae 1 and 2 may be prepared according to the method described in KR Patent Application Laid-Open No. 2007-0003071, and the entire contents of which are incorporated herein by reference.

The olefin-based copolymer having a high molecular weight and a narrow molecular weight distribution and a relatively low elution temperature (Te) and a low hardness can be prepared by using the transition metal compound represented by the formula 1 and the transition metal compound represented by the formula 2 together in a certain equivalent ratio.

The transition metal compound of Formula 1 and the transition metal compound of Formula 2 may be used alone or in combination including one or more cocatalyst compounds represented by the following Formula 3, Formula 4 and Formula 5 in addition to the transition metal compound of Formula 1 and the transition metal compound of Formula 2 as a catalyst for the polymerization reaction. —[Al(R ₇)—O]_(a)—  [Formula 3] A(R ₇)₃  [Formula 4] [L-H]⁺[W(D)₄]⁻ or [L]⁺[W(D)₄]⁻  [Formula 5]

In Formulae 3 to 5,

R₇ may be the same or different, and are each independently selected from the group consisting of a halogen, a hydrocarbyl having 1 to 20 carbon atoms, and a hydrocarbyl having 1 to 20 carbon atoms substituted with a halogen,

A is aluminum or boron,

D each independently represents an aryl having 6 to 20 carbon atoms or an alkyl having 1 to 20 carbon atoms in which at least one hydrogen atom may be substituted with a substituent selected from the group consisting of a halogen, a hydrocarbon having 1 to 20 carbon atoms, an alkoxy having 1 to 20 carbon atoms and an aryloxy having 6 to 20 carbon atoms,

H is a hydrogen atom,

L is a neutral or cationic Lewis acid,

W is a Group 13 element, and

a is an integer of 2 or more.

Examples of the compound represented by Formula 3 include alkylaluminoxanes such as methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane, butylaluminoxane and the like, and modified alkyl aluminoxanes having two or more of the alkylaluminoxanes mixed therein, and specifically may be methyl aluminoxane and modified methyl aluminoxane (MMAO).

Examples of the compound represented by Formula 4 include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, tri-iso-propyl aluminum, tri-sec-butyl aluminum, tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyldimethyl aluminum, methyldiethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron, tributyl boron and the like, and specifically, may be selected from trimethyl aluminum, triethyl aluminum and triisobutyl aluminum.

Examples of the compound represented by Formula 5 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl) boron, trimethylammonium tetra(o,p-dimethylphenyl) boron, tributylammonium tetra(p-trifluoromethylphenyl) boron, trimethylammonium tetra(p-trifluoromethylphenyl) boron, tributylammonium tetrapentafluorophenylboron, N,N-diethylanilinium tetraphenylboron, N,N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron, trimethylphosphonium tetraphenylboron, dimethylanilinium tetrakis(pentafluorophenyl) borate, triethylammonium tetraphenyl aluminum, tributylammonium tetraphenyl aluminum, trimethylammonium tetraphenyl aluminum, tripropylammonium tetraphenyl aluminum, trimethylammonium tetra(p-tolyl) aluminum, tripropylammonium tetra(p-tolyl) aluminum, triethylammoniumtetra (o,p-dimethylphenyl) aluminum, tributylammonium tetra(p-trifluoromethylphenyl) aluminum, trimethylammonium tetra(p-trifluoromethylphenyl) aluminum, tributylammonium tetrapentafluorophenyl aluminum, N,N-diethylanilinium tetraphenyl aluminum, N,N-diethylanilinium tetrapentafluorophenyl aluminum, diethylammonium tetrapentafluorophenyl aluminum, triphenylphosphonium tetraphenyl aluminum, trimethylphosphonium tetraphenyl aluminum, tripropylammonium tetra(p-tolyl) boron, triethylammonium tetra(o,p-dimethylphenyl) boron, triphenylcarbonium tetra(p-trifluoromethylphenyl) boron, triphenylcarbonium tetrapentafluorophenylboron and the like.

The catalyst composition may be prepared by a method including the steps of 1) bringing a primary mixture of a transition metal compound represented by Formula 1 and a transition metal compound represented by Formula 2 into contact with a compound represented by Formula 3 or 4 to obtain a mixture; and 2) adding a compound represented by Formula 5 to the mixture, as the first method.

Further, the catalyst composition may be prepared by a method of bringing a transition metal compound represented by Formula 1 and a transition metal compound represented by Formula 2 into contact with a compound represented by Formula 3, as the second method.

In the first method among the above-described preparation methods of the catalyst composition, the molar ratio of the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2/the compound represented by Formula 3 or 4 may be in the range of 1/5,000 to 1/2, specifically in the range of 1/1000 to 1/10, and more specifically in the range of 1/500 to 1/20.

When the molar ratio of the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2/the compound represented by Formula 3 or 4 exceeds 1/2, the amount of the alkylating agent is very small, and thus the alkylation of the metal compound is not fully carried out. When the molar ratio is less than 1/5000, the alkylation of the metal compound is carried out, but the activation of the alkylated metal compound is not fully achieved due to the side reaction between the remaining excess alkylating agent and the activating agent which is a compound of Formula 5. Further, the molar ratio of the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2/the compound represented by Formula 5 may be in the range of 1/25 to 1, specifically in the range of 1/10 to 1, and more specifically in the range of 1/5 to 1. When the molar ratio of the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2/the compound represented by Formula 5 is more than 1, the amount of the activator is relatively small, so that the metal compound is not fully activated, and thus the activity of the resulting catalyst composition may be lowered. When the molar ratio is less than 1/25, the activation of the metal compound is fully performed, but the unit cost of the catalyst composition may not be economical due to the remaining excess activator, or the purity of the produced polymer may be lowered.

In the second method among the above-described preparation methods of the catalyst composition, the molar ratio of the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2/the compound represented by Formula 3 may be in the range of 1/10,000 to 1/10, and specifically in the range of 1/5000 to 1/100, and more specifically in the range of 1/3000 to 1/500. When the molar ratio is more than 1/10, the amount of the activator is relatively small, so that the activation of the metal compound is not fully achieved, and thus the activity of the resulting catalyst composition may be lowered. When the molar ratio is less than 1/10,000, the activation of the metal compound is fully performed, but the unit cost of the catalyst composition may not be economical due to the remaining excess activator, or the purity of the produced polymer may be lowered.

In the preparation of the catalyst composition, a hydrocarbon-based solvent such as pentane, hexane, heptane or the like, or an aromatic solvent such as benzene, toluene or the like may be used as a reaction solvent.

Further, the catalyst composition may include the transition metal compound and a cocatalyst compound in the form of being supported on a carrier.

The carrier may be used without any particular limitation as long as it is used as a carrier in a metallocene catalyst. Specifically, the carrier may be silica, silica-alumina, silica-magnesia or the like, and any one or a mixture of two or more thereof may be used.

In the case where the support is silica, there are few catalysts liberated from the surface during the olefin polymerization process since the silica carrier and the functional groups of the metallocene compound of Formula 1 form a chemical bond. As a result, it is possible to prevent the occurrence of fouling of the wall surface of the reactor or the polymer particles entangled with each other during the preparation process of the olefin-based polymer. Further, the olefin-based polymer prepared in the presence of the catalyst containing the silica carrier has an excellent particle shape and apparent density of the polymer.

More specifically, the carrier may be high-temperature dried silica or silica-alumina containing a siloxane group having high reactivity on the surface through a method such as high-temperature drying.

The carrier may further include an oxide, carbonate, sulfate or nitrate component such as Na₂O, K₂CO₃, BaSO₄, Mg(NO₃)₂ or the like.

The polymerization reaction for polymerizing the olefin-based monomer may be carried out by a conventional process applied to the polymerization of olefin monomers such as continuous solution polymerization, bulk polymerization, suspension polymerization, slurry polymerization, emulsion polymerization or the like.

The polymerization reaction of olefin monomers may be carried out in the presence of an inert solvent, and examples of the inert solvent include benzene, toluene, xylene, cumene, heptane, cyclohexane, methylcyclohexane, methylcyclopentane, n-hexane, 1-hexene and 1-octene, but the present invention is not limited thereto.

The polymerization of the olefin-based polymer may be carried out at a temperature of from about 25° C. to about 500° C., and specifically at a temperature in the range of 80° C. to 250° C., and more preferably in the range of 100° C. to 200° C. Further, the reaction pressure at the time of polymerization may be in the range of 1 kgf/cm² to 150 kgf/cm², preferably 1 kgf/cm² to 120 kgf/cm², and more preferably 5 kgf/cm² to 100 kgf/cm².

Due to having improved physical properties, the olefin-based polymer of the present invention may be used for blow molding, extrusion molding or injection molding in diverse fields and uses including wrapping, construction, daily supplies, or the like, such as a material of an automobile, a wire, a toy, a fiber, a medicine, or the like. Particularly, the olefin-based polymer may be used for an automobile which requires excellent impact strength.

Further, the olefin-based polymer of the present invention may be usefully used in the production of molded articles.

The molded article may particularly include a blow molded article, an inflation molded article, a cast molded article, an extrusion laminate molded article, an extrusion molded article, a foamed molded article, an injection molded article, a sheet, a film, a fiber, a monofilament, a non-woven fabric, or the like.

BEST MODE FOR CARRYING OUT THE INVENTION Examples

Hereinafter, the present invention will be explained in particular with reference to the following examples.

However, the following examples are illustrated to assist the understanding of the present invention, and the scope of the present invention is not limited thereto.

Preparation Example 1 Preparation of Transition Metal Compound 1 (1) Preparation of 8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline

(i) Preparation of Lithium Carbamate

1,2,3,4-tetrahydroquinoline (13.08 g, 98.24 mmol) and diethyl ether (150 mL) were put into a Schlenk flask. The above-described Schlenk flask was immersed in a low-temperature bath at −78° C. formed of dry ice and acetone, and stirred for 30 minutes. Subsequently, n-BuLi (39.3 mL, 2.5 M, 98.24 mmol) was added thereto via syringe under a nitrogen atmosphere, and thereby pale yellow slurry was formed. Then, after the flask was stirred for 2 hours, the temperature of the flask was raised to room temperature while removing the produced butane gas. The flask was immersed again in a low-temperature bath at −78° C. to lower a temperature, and then CO₂ gas was introduced thereto. As carbon dioxide gas was introduced, the slurry disappeared and the solution became clear. The flask was connected to a bubbler to remove the carbon dioxide gas, and the temperature was raised to room temperature. Thereafter, an excess amount of CO₂ gas and a solvent were removed under vacuum. The flask was transferred to a dry box, and pentane was added thereto, followed by vigorous stirring and filtration to obtain lithium carbamate which is a white solid compound. The white solid compound is coordinated with diethyl ether. The yield is 100%.

¹H NMR (C₆D₆, C₅D₅N) δ 1.90 (t, J=7.2 Hz, 6H, ether), 1.50 (br s, 2H, quin-CH₂), 2.34 (br s, 2H, quin-CH₂), 3.25 (q, J=7.2 Hz, 4H, ether), 3.87 (br s, 2H, quin-CH₂), 6.76 (br d, J=5.6 Hz, 1H, quin-CH) ppm

¹³C NMR (C₆D₆): δ 24.24, 28.54, 45.37, 65.95, 121.17, 125.34, 125.57, 142.04, 163.09 (C═O) ppm

(ii) Preparation of 8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline

The lithium carbamate compound prepared in Step (i) (8.47 g, 42.60 mmol) was put into a Schlenk flask. Then, tetrahydrofuran (4.6 g, 63.9 mmol) and 45 mL of diethyl ether were added in sequence. The Schlenk flask was immersed in a low-temperature bath at −20° C. including acetone and a small amount of dry ice and stirred for 30 minutes, and then t-BuLi (25.1 mL, 1.7 M, 42.60 mmol) was added. At this time, the color of the reaction mixture turned red. The mixture was stirred for 6 hours while a temperature was maintained at −20° C. A CeCl₃.2LiCl solution (129 mL, 0.33 M, 42.60 mmol) dissolved in tetrahydrofuran and tetramethylcyclopentinone (5.89 g, 42.60 mmol) were mixed in a syringe, and then introduced into the flask under a nitrogen atmosphere. The temperature of the flask was slowly raised to room temperature. After 1 hour, a thermostat was removed and the temperature was maintained at room temperature. Subsequently, water (15 mL) was added to the flask, and ethyl acetate was added thereto, followed by filtration to obtain a filtrate. The filtrate was transferred to a separatory funnel, followed by the addition of hydrochloric acid (2 N and 80 mL) and shaking for 12 minutes. A saturated aqueous solution of sodium hydrogencarbonate (160 mL) was added for neutralization, and then an organic layer was extracted. Anhydrous magnesium sulfate was added to the organic layer to remove moisture, followed by filtration, and the filtrate was taken to remove the solvent. The obtained filtrate was purified by column chromatography using hexane and ethyl acetate (v/v, 10:1) to obtain yellow oil. The yield was 40%.

¹H NMR (C₆D₆): δ 1.00 (br d, 3H, Cp-CH₃), 1.63-1.73 (m, 2H, quin-CH₂), 1.80 (s, 3H, Cp-CH₃), 1.81 (s, 3H, Cp-CH₃), 1.85 (s, 3H, Cp-CH₃), 2.64 (t, J=6.0 Hz, 2H, quin-CH₂), 2.84-2.90 (br, 2H, quin-CH₂), 3.06 (br s, 1H, Cp-H), 3.76 (br s, 1H, N—H), 6.77 (t, J=7.2 Hz, 1H, quin-CH), 6.92 (d, J=2.4 Hz, 1H, quin-CH), 6.94 (d, J=2.4 Hz, 1H, quin-CH) ppm

(2) Preparation of [(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-η⁵,k-N]titanium dimethyl)

(i) Preparation of [(1,2,3,4-tetrahydroquinolin-8-yl) tetramethylcyclopentadienyl-η⁵,κ-N] dilithium compound

After 8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline (8.07 g, 32.0 mmol) prepared by Step (1) and 140 mL of diethyl ether were put in a round flask in a dry box, a temperature was lowered to −30° C. and n-BuLi (17.7 g, 2.5 M, 64.0 mmol) was slowly added while stirring. The reaction was allowed to proceed for 6 hours while the temperature was raised to room temperature.

Thereafter, the solid was obtained by filtration while washing with diethyl ether several times. A vacuum was applied to remove the remaining solvent to obtain a di-lithium compound (9.83 g) which is a yellow solid. The yield was 95%.

¹H NMR (C₆D₆, C₅D₅N) δ 2.38 (br s, 2H, quin-CH₂), 2.53 (br s, 12H, Cp-CH₃), 3.48 (br s, 2H, quin-CH₂), 4.19 (br s, 2H, quin-CH₂), 6.77 (t, J=6.8 Hz, 2H, quin-CH), 7.28 (br s, 1H, quin-CH), 7.75 (brs, 1H, quin-CH) ppm

(ii) Preparation of (1,2,3,4-tetrahydroquinolin-8-yl) tetramethylcyclopentadienyl-η⁵,κ-N]titanium dimethyl

In a dry box, TiCl₄-DME (4.41 g, 15.76 mmol) and diethyl ether (150 mL) were put into a round flask and MeLi (21.7 mL, 31.52 mmol and 1.4 M) was slowly added while stirring at −30° C. After stirring for 15 minutes, [(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-η⁵,κ-N] dilithium compound (5.30 g, 15.76 mmol) prepared in Step (i) was put into the flask. The mixture was stirred for 3 hours while the temperature was raised to room temperature. After completion of the reaction, the solvent was removed by vacuum, the mixture was dissolved in pentane and filtered to obtain the filtrate. A vacuum was applied to remove pentane to obtain a dark brown compound (3.70 g). The yield was 71.3%.

¹H NMR (C₆D₆) δ 0.59 (s, 6H, Ti—CH₃), 1.66 (s, 6H, Cp-CH₃), 1.69 (br t, J=6.4 Hz, 2H, quin-CH₂), 2.05 (s, 6H, Cp-CH₃), 2.47 (t, J=6.0 Hz, 2H, quin-CH₂), 4.53 (m, 2H, quin-CH₂), 6.84 (t, J=7.2 Hz, 1H, quin-CH), 6.93 (d, J=7.6 Hz, quin-CH), 7.01 (d, J=6.8 Hz, quin-CH) ppm

¹³C NMR (C₆D₆): δ 12.12, 23.08, 27.30, 48.84, 51.01, 119.70, 119.96, 120.95, 126.99, 128.73, 131.67, 136.21 ppm

Preparation Example 2: Preparation of Transition Metal Compound 2 (1) Preparation of 2-methyl-7-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl) indoline

2-methyl-7-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl) indoline was prepared in the same manner as in (1) of Preparation Example 1 except that 2-methylindoline was used instead of 1,2,3,4-tetrahydroquinoline in (1)(i) of Preparation Example 1. The yield was 19%.

¹H NMR (C₆D₆): δ 6.97 (d, J=7.2 Hz, 1H, CH), δ 6.78 (d, J=8 Hz, 1H, CH), δ 6.67 (t, J=7.4 Hz, 1H, CH), δ 3.94 (m, 1H, quinoline-CH), δ 3.51 (br s, 1H, NH), δ 3.24-3.08 (m, 2H, quinoline-CH₂, Cp-CH), δ 2.65 (m, 1H, quinoline-CH₂), δ 1.89 (s, 3H, Cp-CH₃), δ 1.84 (s, 3H, Cp-CH₃), δ 1.82 (s, 3H, Cp-CH₃), δ 1.13 (d, J=6 Hz, 3H, quinoline-CH₃), δ 0.93 (3H, Cp-CH₃) ppm.

(2) Preparation of [(2-methylindolin-7-yl)tetramethylcyclopentadienyl-eta5,kappa-N]titanium dimethyl)

(i) A di-lithium salt compound (4 g) in which 0.58 equivalent of diethyl ether was coordinated was obtained (1.37 g, 50%) in the same manner as in (2) (i) of Preparation Example 1 except that 2-methyl-7-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-indoline (2.25 g, 8.88 mmol) was used instead of 8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.

¹H NMR (Pyridine-d8): δ 7.22 (br s, 1H, CH), δ 7.18 (d, J=6 Hz, 1H, CH), δ 6.32 (t, 1H, CH), δ 4.61 (brs, 1H, CH), δ 3.54 (m, 1H, CH), δ 3.00 (m, 1H, CH), δ 2.35-2.12 (m, 13H, CH, Cp-CH₃), δ 1.39 (d, indoline-CH₃) ppm.

(ii) A titanium compound was prepared in the same manner as in (2) (ii) of Preparation Example 1 using the di-lithium salt compound (1.37 g, 4.44 mmol) prepared in the above (i).

¹H NMR (C₆D₆): δ 7.01-6.96 (m, 2H, CH), δ 6.82 (t, J=7.4 Hz, 1H, CH), δ 4.96 (m, 1H, CH), δ 2.88 (m, 1H, CH), δ 2.40 (m, 1H, CH), δ 2.02 (s, 3H, Cp-CH₃), δ 2.01 (s, 3H, Cp-CH₃), δ 1.70 (s, 3H, Cp-CH₃), δ 1.69 (s, 3H, Cp-CH₃), δ 1.65 (d, J=6.4 Hz, 3H, indoline-CH₃), δ 0.71 (d, J=10 Hz, 6H, TiMe₂-CH₃) ppm.

Example 1

A 1.5 L-continuous process reactor was filled with a hexane solvent (5 kg/h) and 1-octene (1.5 kg/h), and a temperature at the top of the reactor was preheated to 140.7° C. A triisobutyl aluminum compound (0.05 mmol/min), a mixture (0.5 μmol/min) of a transition metal compound obtained by mixing the transition metal compound 1 obtained in Preparation Example 1 and the transition metal compound 2 obtained in Preparation Example 2 in a molar ratio of 1:3, and a dimethylanilinium tetrakis(pentafluorophenyl) borate cocatalyst (1.5 μmol/min) were simultaneously introduced into the reactor. Subsequently, ethylene (0.87 kg/h) was then fed into the reactor, and the copolymerization reaction was continued at 140.7° C. for 30 minutes or more in a continuous process at a pressure of 89 bar to obtain a copolymer. After drying for more than 12 hours in a vacuum oven, the physical properties were measured.

Examples 2 to 5

The copolymerization reaction was carried out using the two transition metal catalysts as in Example 1. The ratio of the two transition metals, the ratio of the catalyst to the cocatalyst, the reaction temperature and the amount of the comonomer were changed as shown in the following Table 1. The reaction proceeded to obtain a copolymer.

Comparative Example 1

Solumer851L manufactured by SK Global Chemical Co., LTD. was purchased and used.

Comparative Example 2

EG8842 manufactured by the Dow Chemical Company was purchased and used.

Comparative Example 3

The copolymerization reaction was carried out by using the same method as in Example 1 to obtain a copolymer except that only the transition metal compound 1 was used as a catalyst.

Comparative Example 4

The copolymerization reaction was carried out in the same manner as in Example 1 to obtain a copolymer except that only the transition metal compound 2 was used as the catalyst.

Comparative Example 5

The copolymerization reaction was carried out using the two transition metal catalysts as in Example 1. The ratio of the two transition metals, the ratio of the catalyst to the cocatalyst, the reaction temperature and the amount of the comonomer were changed as shown in the following Table 1. The reaction proceeded to obtain a copolymer.

TABLE 1 Catalyst ratio Reaction Catalyst (Transition metal Cocatalyst TiBAl Ethylene 1-octene temperature (μmol/min) compound 1:2) (μmol/min) (mmol/min) (kg/h) (kg/h) (° C.) Example 1 0.5 1:3 1.5 0.05 0.87 5 140.7 Example 2 0.55 1:3 1.65 0.6 0.87 5 145.2 Example 3 0.55 1:2 1.65 0.5 0.87 5 144.5 Example 4 0.5 1:3 1.5 0.04 0.87 5 140.7 Example 5 0.28 1:3 1.65 0.5 0.87 5 150.6 Comparative 0.5 — 1.5 0.05 0.87 5 140.7 Example 1 Comparative 0.55 — 1.65 0.6 0.87 5 145.2 Example 2 Comparative 0.2 — 0.35 0.04 0.87 5 139 Example 3 Comparative 0.38 — 1.14 0.05 0.87 5 135.7 Example 4 Comparative 0.27 1:8 0.81 0.04 0.87 1.3 141.5 Example 5

Experimental Example

The physical properties of the copolymers of Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated according to the following methods, and the results are shown in the following Table 2 and 3.

1) Density of Polymer

Measurement was performed in accordance with ASTM D-792.

2) Melt Index (MI) of Polymer

Measurement was performed in accordance with ASTM D-1238 [condition E, 190° C. and a load of 2.16 kg].

3) Melting Point (Tm) of Polymer

The melting point was obtained using the differential scanning calorimeter (DSC) 6000 manufactured by PerkinElmer. That is, after the temperature was increased to 200° C., the temperature was maintained at that temperature for 1 minute, then decreased to −100° C., and the temperature was increased again to obtain the top of the DSC curve as the melting point. At this time, the rate of temperature rise and fall is 10° C./min, and the melting point is obtained during the second temperature rise.

4) Weight Average Molecular Weight (Mw, g/Mol) and Molecular Weight Distribution (MWD)

The number-average molecular weight (Mn) and the weight-average molecular weight (Mw) each were measured by gel permeation chromatography (GPC), and the molecular weight distribution was calculated by dividing the weight average molecular weight by the number average molecular weight.

Column: PL Olexis

Solvent: Trichlorobenzene (TCB)

Flow rate: 1.0 ml/min

Concentration of specimen: 1.0 mg/ml

Injection amount: 200 μl

Column temperature: 160° C.

Detector: Agilent High Temperature RI detector

Standard: Polystyrene (Calibration using cubic function)

5) Soluble Fraction, Weight Average Molecular Weight (Mw) of Soluble Fraction and Elution Termination Temperature

The measurement equipment was a CFC of Polymer Char. First, a solution of the copolymer was fully dissolved in an oven at 130° C. for 60 minutes in a CFC analyzer using o-dichlorobenzene as a solvent, poured into a TREF column adjusted to 135° C., and then cooled to 95° C. and stabilized for 45 minutes. Subsequently, the temperature of the TREF column was lowered to −20° C. at a rate of 0.5° C./min, and then maintained at −20° C. for 10 minutes. Thereafter, the elution amount (mass %) was measured using an infrared spectrophotometer. Subsequently, the operation of raising the temperature of the TREF column to a predetermined temperature at a rate of 20° C./min and maintaining a temperature reached for a predetermined time (i.e., about 27 minutes) was repeated until the temperature of the TREF column reached 130° C., and the amount of eluted fraction (mass %) was measured during each temperature range. The fraction eluted at each temperature was sent to a GPC column, and the molecular weight Mw was measured in the same manner as in the GPC measurement, except that o-dichlorobenzene was used as a solvent.

The content of the ultra-low crystalline region means the content of the fraction eluted at −20° C. or less, and the molecular weight Mw was measured using a GPC column of CFC. The elution termination temperature was defined as the final temperature at which no more fractions were eluted in the detector.

6) Hardness (Shore A)

The hardness was measured in accordance with ASTM D2240 standard using a GC610 STAND for Durometer manufactured by TECLOCK Corporation and a Type A-shore hardness tester manufactured by Mitutoyo Chemical Co., Ltd.

TABLE 2 Elution SF termination Density MI Tm (CFC) temperature Mw of Shore (g/mL) (g/10 min) (° C.) Mw MWD (wt %) (° C.) SF hardness A Example 1 0.856 1.07 32.5 131K 2.29 27.5 31 104827 41 Example 2 0.859 0.97 38.7 128K 2.08 16.8 34 82474 45 Example 3 0.857 1.10 35.2 122K 2.08 25.3 31 60064 43 Example 4 0.855 1.74 28.9 112K 2.15 40.7 28 161537 39 Example 5 0.861 1.02 42.2 126K 2.16 10.7 40 102736 47 Comparative 0.859 1.06 44.4 130K 2.36 14.6 34 40675 51 Example 1 Comparative 0.859 0.95 43.1 132K 2.02 5.3 52 135552 50 Example 2 Comparative 0.858 1.44 36.3 120K 2.01 5.8 37 191817 49.0 Example 3 Comparative 0.861 1.19 38.8 124K 2.03 1.4 40 50581 53 Example 4 Comparative 0.861 0.59 44.5 154K 2.32 5.5 76 43971 57 Example 5

TABLE 3 Equation 2 or 3 Satisfying A of Tm × (0.855 × Tm − Equation Equation 62) < A < d × −1238 1 and Density Tm Shore 1 (H = 1293 × d × −1238 < A < Tm × Equation (g/mL) (° C.) hardness A d + A) (0.855 × Tm − 62) 2 or 3 Example 1 0.856 32.5 41 −1065.81 −1111.91 < ◯ A < −1059.73 Example 2 0.859 38.7 45 −1065.69 −1118.88 < ◯ A < −1063.44 Example 3 0.857 35.2 43 −1065.1 −1123.02 < ◯ A < −1060.97 Example 4 0.855 28.9 39 −1066.52 −1077.70 < ◯ A < −1058.49 Example 5 0.861 42.2 47 −1066.27 −1093.78 < ◯ A < −1065.92 Comparative 0.859 44.4 51 −1059.69 −1067.29 < X Example 1 A <−1063.44 Comparative 0.859 43.1 50 −1060.69 −1083.94 < X Example 2 A < −1063.44 Comparative 0.858 36.3 49.0 −1060.39 −1123.98 < X Example 3 A < −1062.20× Comparative 0.861 38.8 53 −1060.27 −1118.45 < X Example 4 A < −1065.92 Comparative 0.861 44.5 57 −1056.273 −1065.92 < X Example 5 A < −1065.89

In Table 2, the elution termination temperature is defined as the final temperature at which the fraction is no longer eluted in the detector, and a low elution termination temperature is a general feature of low-density olefin-based polymers which are distinguished from polymers having high density or high crystallinity such as LDPE, HDPE, LLDPF, etc.

In Table 2, the higher the SF (>8%), the lower the hardness and the higher the impact strength at compounding, but it is very difficult to increase the SF content at the same density to a certain level or more. Even if the SF content is increased as in Comparative Example 1, the molecular weight of the fraction is lowered, which is detrimental to the anti-blocking properties. The copolymers of the Examples have excellent impact strength and anti-blocking properties by maintaining the molecular weight of the fraction high while maintaining the SF content high. 

The invention claimed is:
 1. An olefin-based polymer, which has (1) a density (d) ranging from 0.850 g/cc to 0.865 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min, (3) a melt temperature (Tm) of 10° C. to 100° C., and (4) a hardness (H, Shore A) defined by the following Equation 1: H=1293×d+A,  [Equation 1] in Equation 1, A satisfies Equation 2 or Equation 3 below: Tm×(0.855×Tm−62)<A<d×−1238,  [Equation 2] d×−1238<A<Tm×(0.855×Tm−62),  [Equation 3] in Equations 1 to 3, H is the hardness (shore A), d is the density, and Tm is the melt temperature.
 2. The olefin-based polymer according to claim 1, wherein the olefin-based polymer has (5) a soluble fraction (SF) of 8 wt % or more at −20° C. in cross-fractionation chromatography (CFC), in which a weight average molecular weight (Mw) of the soluble fraction is in a range of 50,000 g/mol to 120,000 g/mol.
 3. The olefin-based polymer according to claim 1, wherein the olefin-based polymer has (6) a molecular weight distribution (MWD) in a range of 1.0 to 3.0.
 4. The olefin-based polymer according to claim 1, wherein the olefin-based polymer has (7) a weight average molecular weight (Mw) in a range of 10,000 to 500,000.
 5. The olefin-based polymer according to claim 1, wherein the hardness (Shore A) of the olefin-based polymer is 50 or less.
 6. The olefin-based polymer according to claim 1, wherein the melt index (MI) of the olefin-based polymer is in a range of 0.5 g/10 min to 2.0 g/10 min.
 7. The olefin-based polymer according to claim 1, wherein the hardness (shore A) of the olefin-based polymer is in a range of 30 to 50, when the density of the olefin-based polymer is in a range of 0.855 g/cc to 0.865 g/cc and the melt index (MI) of the olefin-based polymer is in a range of 0.95 g/10 min to 1.2 g/10 min.
 8. The olefin-based polymer according to claim 1, wherein the olefin-based polymer is a copolymer of ethylene and an alpha-olefin comonomer having 3 to 12 carbon atoms.
 9. The olefin-based polymer according to claim 8, wherein the alpha-olefin comonomer includes any one selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, or a mixture of at least two thereof.
 10. The olefin-based polymer according to claim 8, wherein the alpha-olefin comonomer is in an amount of 90 wt % or less.
 11. The olefin-based polymer according to claim 1, wherein the olefin-based polymer is a copolymer of ethylene and 1-octene.
 12. The olefin-based polymer according to claim 1, wherein the olefin-based polymer is obtained by a method of preparing an olefin-based polymer including a step of polymerizing an olefin-based monomer in the presence of a catalyst composition for olefin polymerization including a transition metal compound represented by the following Formula 1 and a transition metal compound represented by the following Formula 2 in a molar ratio of 1:1 to 1:5:

in Formula 1, R₁s are the same or different, and each R₁ independently represents hydrogen, an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, an aryl, a silyl, an alkylaryl, an arylalkyl or a metalloid radical of a Group 4 metal substituted with a hydrocarbyl; R₂s are the same or different, and each R₂ independently represents hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; an aryl; an alkoxy; an aryloxy; or an amido radical, and two or more of the R₂s are optionally connected to each other to form an aliphatic ring or an aromatic ring; R₃s are the same or different, and each R₃ independently represents hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; or an aliphatic or aromatic ring which contains nitrogen and is substituted with an aryl radical or unsubstituted, and when a number of substituents is plural, the substituents are optionally connected to each other to form an aliphatic or aromatic ring; M₁ is a Group 4 transition metal; and Q₁ and Q₂ each independently represent a halogen; an alkyl having 1 to 20 carbon atoms; an alkenyl; an aryl; an alkylaryl; an arylalkyl; an alkylamido having 1 to 20 carbon atoms; or an arylamido;

in Formula 2, R₄s are the same or different, and each R₄ independently represents hydrogen, an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, an aryl, a silyl, an alkylaryl, an arylalkyl or a metalloid radical of a Group 4 metal substituted with a hydrocarbyl; R₅s are the same or different, and each R₅ independently represents hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; an aryl; an alkoxy; an aryloxy; or an amido radical, and two or more of the R₅s are optionally connected to each other to form an aliphatic ring or an aromatic ring; R₆s are the same or different, and each R₆ independently represents hydrogen; a halogen; an alkyl having 1 to 20 carbon atoms; or an aliphatic or aromatic ring which contains nitrogen and is substituted with an aryl radical or unsubstituted, and when a number of substituents is plural, the substituents are optionally connected to each other to form an aliphatic or aromatic ring; M₂ is a Group 4 transition metal; and Q₃ and Q₄ each independently represent a halogen; an alkyl having 1 to 20 carbon atoms; an alkenyl; an aryl; an alkylaryl; an arylalkyl; an alkylamido having 1 to 20 carbon atoms; or an arylamido.
 13. The olefin-based polymer according to claim 12, wherein the olefin-based polymer is prepared by a continuous solution polymerization reaction using a continuous stirred tank reactor in the presence of the catalyst composition for olefin polymerization.
 14. The olefin-based polymer according to claim 12, wherein the transition metal compound represented by Formula 1 is one or more selected from the group consisting of the following Formulae 1-1 and 1-2, and the transition metal compound represented by Formula 2 has the following Formula 2-1:


15. An olefin-based polymer, which has: a density (d) ranging from 0.850 g/cc to 0.865 g/cc; a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min; a soluble fraction (SF) of 10 wt % or more at −20° C. in cross-fractionation chromatography (CFC), in which a weight average molecular weight (Mw) of the soluble fraction is in a range of 50,000 g/mol to 120,000 g/mol; a vinyl group content per 1,000 carbon atoms of 0.06 to 1, which is determined by infrared absorption measurement; a MFR10/MFR2.16 of 8.5 or less, which is a ratio of a melt flow rate measured ASTM D1238 at 190° C. 10 kg load and ASTM D1238 at 190° C. 2.16 kg load; and a hardness (H, Shore A) defined by the following Equation 1: H=1293×d+A,  [Equation 1] in Equation 1, A satisfies Equation 2 or Equation 3 below: Tm×(0.855×Tm−62)<A<d×−1238,  [Equation 2] d×−1238<A<Tm×(0.855×Tm−62),  [Equation 3] in Equations 1 to 3, H is the hardness (shore A), d is the density, and Tm is the melt temperature. 